Apparatus for obtaining metals and alloys.



N0.'883,595, PATBNTBD MAR. 31, 190s.

' E. VIEL.

.APPARATUS FOR OBTAINING METALS AND ALLOYS.

APPLICATION FILED 00T. 29. 1907'.

being treated, and so forth.

- very linelypulverized condition; the` proporwho have taken up thisquestion have failed UMTED sTATirds PATENT omnes.

inirLiirNviEL, or RENNES, ritmes.

` APPARATUS Fon OBTAINING METALS AND ALLoYs.

No."8s3,595.

speiacanon or Letters Patent.

ratented March 31, 1908.

Original application filed Octoberl, 1996, Serial No3-11,494. Dividedand this appiicationvfiled October 29, 1907.

' Serial No. 399,696.

T o all whom fit may concern:

Be it known that l, EMILIEN VIEL', oi" Rennes, France, have invented anew and useful Improvement in .Xpparatus for Obtaining;r Metals andAlloys, which improvement is fully set lforth in the followingspecification.

This is a division of my application i'iled Oei. si, ieee, serial No.341,494.

T his invention relates to apparatus for obtainii'ig' metals and alloysand in particular' aluminiun'i, silicon, magnesium chromium, ete, byreduction of their oxids,`

llitherto numerous attempts have been made by. scientists and engineersto reduee in tl-e electric furnace the refractory oxids, such asalumina, silica, magnesia, and chromite, efe., for the purpose ofobtainiiipr the correspondingl metals. .'l`hese attempts have not beensuccessful because the inventors to realize the necessary conditions intheir processes and their apparatus. The vfirst of these conditions isto raise to the formation tennpcrature, that to say ai'iproximately tothe decomposition temperature, all the. compounds of the known i'netals,and at this moment to cause the intervention of a bod)Y i, capable. ofabsorbing the oxygen, if an oxid is being treated, the clilorin, if aehlorid is l ln the vmost i lgeneral where oxidsfliave to be treated,the appropriate reducing agentis carbon'. In order to comply with thiscomlition, it is necessary to have an apparatus permittiner of obtaininga sul'i'ieiei'itly high tenii'ierature.

rl`he second condition is to form beforehand with the rei l ueinpragent, such as carbon, preferably in the. forni of charcoal, as perfecta mixture as possible, which result may lbe obtained by employing thesebodies. in a tions of the mixture should then be such as. are indicatedby tlze equations of the chemical reaction, forexa m'ple ln the. thii'lpaee care should be taken that when the mixturel has been raised to sueha temperature that deeimiposition vhas i taken place, the metalliberated should immedia (ely be Conducted from the excessively hotdecomposition zone into another relatively .cold mme which is at :itemperature l lower than lhe vohiiili'fcation tenfperature of i theseparated metal. For example, lin the case of alumina, which isdecomposed by carbon at a temperature of about 30000 centigrade andgives aluminium, thc arrznigenient :must be suchfthat immediately afterits separation the aluminium is conducted .into a Zone at a temperaturelower than S000 C., above which temperature aluminium volatilizes. Inthis manner, the combination `of the volatilized metal with oxygenandthe formation of .the oxid is avoided.

Finally the addition of the mixture of; oxid and carbon or otherreducing agent should take place progressively, that is to say, almostin a eoi'itinuous manner, and in small quantities, so that it is onlynecessary immediately to raise to the decomposition temi'ierature oi theoxid small quantities of the mixture which is passing into theexcessively hot zone, and to eileet the conduction of ther metal intothe cold zone very rapidly.

The process in accordance with the present invention therefore consist-sin subjectingI to the decomposition temperature of the oxid or ofthecompound, and this in a continuous manner, small quantities of themixture, which is very intimate and appropriately proportioned, of theoxid or the compound with the reducing body, the metal or alloy arisingfromv the decomposition being immediately conducted in an appropriatemanner into asu'lliciently cold zone, that is to say, a zone at atemperature lower than that of' volatilization of' the metal or of themetals of the separated alloys for the purpose of preventing?rcombination with the oxygen of the air.

lin the followingV description, a workinfev furnace which satisfies theconditions enumerated' above, is referred to by Way of example andillustrated in thc accon'ipanyinr drawings, in which Figures l and 2represent the said furnace in cross-section and in longitudinal sectionrcsiiectively.

The furnace consists essentially of a fusion chamber or crueible o withcarbon walls l) provided with a cover c likewise of carbon, and with asole d havingr a very steep linclination (say, 250 to 30o) this solehavingr rat its lower extremity a water 'circulation e extending forexample over about one-third of the sole.` This chamber ory erucible issurrounded by refractory Walls or coverings of. appropriate thickness,wheh may be confinedin a sheet metal jacket g.

At the lower part of the wall situa-ted at the lowest part of the sole,a tapping hole h of appropriate dimensions is formed, to permit of thedischar e of the metal; there may also be provided a ove this tappinghole a second hole h which is ordinarily stopped'by a plug g of11efractory-material having a carbon extremity, which hole may be usedfor `inspection purposes and for cleaning the sole.

Two electrodes i i of circular or rectan ular or other cross-sectionenter the cham er or crucible horizontally in line one with the other,or inclined, these electrodes passing through appropriateapertures jformed in the walls f, considerable play being left between the walls ofthese apertures andthe electrodes, the said apertures being covered witha protecting layer k of magnesia. These electrodes't i, a're supportedby appropriate bearings or supports l, mounted in slideways in such amanner that the electrodes may be caused to advance or recede byappropriately rotating theendless screws 'm by means of handl wheels a.The object of this arrangement is to permit of a general regulation ofthe arc, and in particular in accordance with the wear of the electrodesto which the current is conducted and which it leaves at the terminals oo. In the wall opposite the wall in which the tapping hole 'is formed, acharging orifice (1 is provided,

and in continuation of it a conduit r surmounted by a hopper s in whichan Archimedean screw p rotates; this screw is operated4 by hand, orcontrolled mechanically in any appropriate manner when the furnace actswith a continuous feed. In the median plane perpendicular to thevertical 'plane passing through the electrodes Aand above the carboncover c, two inclined and symmetrical electromagnets t are jointed onlegs u which rest upon projecting bearings on the supports Z. These twoelectromagnets which may be fed with current in parallel with that ofthe electrodes, or from an independent source, are wound in such amanner that both of them exert a repelling effect upon the arc, so as toblow it and bring it nearer to the sole. As will be understood, the twoeffects of vthese electromagnets combine themselves in such a manner asto exert a resultant effect, the direction of which may be varied eitherby acting upon the inclination ofv one of the electromagnets or of .bothat once, or by placing a greater or smaller number of ampere turns incircuit in one of the-electromagnets by means of an appropriatecommutator. In this manner it is possible to direct the blown arc forthe purpose of locating it in a predetermined zone of the sole, whichzone should always be com-- YWised between the points y marked on thedrawing', that is to say, outside the cold rione, which is situatedabove the water circulation e.

The' reduction process in accordance with this invention is then carriedout with this special furnace in the following mannen- The hopper g ischarged with the appropriately roportioned and pulverized mixture of caronand oxids or compounds to be reduced, and the said mixture is chargedcontinuously or in small quantities on t'o the sole by rotating thescrew p. The mixture falls upon the inclined sole at its upperextremity,

and at once reaches the zone of the blown arc the temperature of whichmay be taken as about- 30000 C. Under the infiuence of this hightemperature, the oXid fuses and decomis advisable to preliminarily heatthe furnace until the desired temperature is obtained.

During the iirst operation the liberated metal may combine with thecarbon of the sole in such a manner as to form a refractory carbid sole.v

lt will be understood that by means of the furnace which has beendescribed, it is possible to realize the conditions of the processbecause a continuous or almost continuous admission of the mixture maybe obtained, and owing to the'very vigorous blowing of the are by meansof exceedingly powerful electromagnets, it may be concentrated in agiven zone as close to the sole as desired and a very high temperatureobtained, and further that owing to the inclination ofthe sole the metalwhen once it has been-separated immediately passes away from theexceedingly hot zone and reaches another relatively cold zone which isobtained as has been indicated by coolingvby a water circulation. Asstated above, this process and this apparatus permit of reducing notonly alumina, but also ehromite, magnesia and silica. In this lattercase, the o )eration takes place more readily because the volatilizationtemperature of silicon is 1650O C., that is to say, much higher thanthat of aluminium, and the difference betweenthe volatilizationtemperature of silicon and the decomposition tcmperature (25000 C.) ofsilica is much less.`

With this' apparatus it is also possible to treat silicates or analogouscompounds in order to obtain compounds or alloys, such asSilico-aluminium, ferro-chromium, etc. In order to obtain pure aluminiumand silicon from Silico-aluminium, it is necessary to heat theSilico-aluminium to 7 00O upon the sole of a reverberatory furnace; thealuminium separates and the silicon remains as residue.

The aluminium thus formed still contains 3% of silicon; in order toobtain it pure, the silicon is burned like carbon ina Bessemerretort.

The process herein described forms the subject-matter of the descriptionand claims of my original, application, Sr. No. 341,494, filed Oct. 31,1906, and is not herein claimed.

What i'sclaimed is: y

In a furnace of the character described, the combination of a cruciblehaving a steeply inclined sole down which the ore charge moves bygravity, oppositely disposed and adjustable electrodes mounted abovesaid sole and in line ofthe moving ore charge,

hinge-su' ported electromagnets havin the axes of t eir coils in planesat right ang es to the vertical plane assing throughzsaid electrodesandadapted), when energized, to blow thearc towards the sole of thefurnace, and.

'means for cooling the sole beyond the heated zone.`

In testimony whereof4 'I have signed this specification inthe presenceof two subscrib-

